11 January 2018, Arctic cause of loopier cold weather? A QUICK SUMMARY: The Science Linking Arctic Warming to This Crazy-Cold Winter: It’s well known that the rapidly warming Arctic is melting sea ice, thawing permafrost, and accelerating sea-level rise. But a growing body of research suggests, counter intuitively, that it could also be amplifying cold snaps, much like the brutal one now freezing the East Coast. ANOTHER VIEW: US cold snap was a freak of nature, quick analysis finds. The cold snap that gripped the East Coast and Midwest region was a rarity that bucks the warming trend, said researcher Claudia Tebaldi of the National Center for Atmospheric Research and the private organization Climate Central.
Category Archives: Mainstreaming Climate Change
4 January 2018: The first complete temperature datasets for 2017 show that last year was the third in a row of exceptionally warm years, the Copernicus Climate Change Service (C3S) implemented by the European Weather Centre (ECMWF) can announce. One data set, produced by ECMWF, shows that the global average surface air temperature exceeded 14.7°C, making 2017:
- about 0.1°C cooler than the warmest year on record, 2016, and warmer than the previous second warmest year, 2015
- the warmest year on record not influenced by warming El Niño conditions in the tropical Pacific
- around 0.5°C warmer than the 1981–2010 climatological reference period
- an estimated 1.2°C warmer than the pre-industrial value for the 18th century.
Comparable results have been obtained by C3S from a reanalysis dataset produced by the Japan Meteorological Agency (JMA). The method used to produce the datasets is to combine millions of meteorological and marine observations, including from satellites, with models to produce a complete reanalysis of the atmosphere. The combination of observations with models makes it possible to estimate temperatures at any time and in any place across the globe, even in data-sparse areas such as the polar regions. The results support the provisional announcement by the World Meteorological Organization (WMO) two months ago that 2017 was set to be among the three warmest years on record. Other datasets used in the WMO announcement, which are derived from monthly climatological data for a smaller number of long-term observing sites, are also expected to concur when they are released shortly. All datasets will contribute to the consolidated statement to be issued by WMO on 2017 temperatures. Read More here
19 December 2017, DeSmog, Pruitt’s Plan to Debate Climate Science Paused as Science Confirms Human Link to Extreme Weather. The same week that a slew of new scientific reports confirmed just how much humans are changing the climate, and in turn, the rest of the planet, Environmental Protection Agency Chief Scott Pruitt’s plans for a “Red Team, Blue Team” debate of this very same science were put on hold. The military-style exercise that would falsely pit the overwhelming majority of climate scientists against a handful of non-experts is an eight-year-old talking point of the notorious climate-denying think tank the Heartland Institute (which is likely not surprised by this development). Meanwhile, last week in New Orleans, several groups of prominent climate scientists shared their latest findings at the world’s largest gathering of Earth and planetary scientists. The roughly 25,000 attendees of the American Geophysical Union annual meeting included scientific leaders from academia, government, and the private sector. Clear and Present Climate Science These peer-reviewed reports make it clear that any meaningful climate debate in the future should not be over the degree of humanity’s role in climate change, but to what degree the climate has changed already and what can be done to stop it. The American Meteorological Society’s 2016 “State of the Climate” report offers the first examples of extreme weather events not possible in a preindustrial climate. “Climate change was a necessary condition for some of these events in 2016, in order for them to happen,” Jeff Rosenfeld, editor in chief of the Bulletin of the American Metrological Society, said at a press conference. “These are new weather extremes made possible by a new climate. They were impossible in the old climate.” Read more here
14 December 2017, The Conversation, Not just heat: even our spring frosts can bear the fingerprint of climate change. In recent years, scientists have successfully identified the human fingerprint on hot years, heatwaves, and a range of other temperature extremes around the world. But as everyone knows, climate change affects more than just temperature. The “signal” of human-induced climate change is not always clear in other weather events, such as cold snaps or episodes of extreme rainfall. Three new studies, released today as part of a special edition of the Bulletin of the American Meteorological Society, take a closer look at two such events, both of which happened in southern Australia in mid-2016: the frosts that hit Western Australia’s South West, and the extremely wet weather that hit much of southeastern Australia during that year’s winter and early spring. Perhaps surprisingly, WA’s frosts showed a fingerprint of climate change, due to changes in weather patterns. Meanwhile, there was very little climate change signal in the extreme rainfall that hit the southeast. While there is a clear human-driven upward trend in Australia’s average temperatures and the future of southern Australia is projected to be dry in the cool seasons, last year Australia experienced its wettest winter and September on record. Meanwhile, September in WA’s South West brought up to 18 frost nights across the region – the most on record in some locations. An increasing temperature trend would limit the number of extreme cold events, and broadly speaking this is true for Australia. So what caused the record frost risk in South West WA in September 2016? For the northern hemisphere, a “wobbly” jet stream has been proposed as the cause of periodic blasts of extreme cold weather. In this theory, human-driven changes to atmospheric circulation cause Arctic air to temporarily extend southwards over populated areas, bringing Arctic weather in spite of the background warming trend. But this kind of theory hasn’t been examined in depth for Australia. Read More here